Monitoring Editor: Randy Schekman SNARE proteins are key components of the fusion machinery in vesicular transport and in homotypic membrane fusion. We previously found that ArfGAPs promoted a conformational change on SNAREs, which allowed recruitment of the small GTPase Arf1p in stoichiometric amounts. Here we show that the ArfGAP Gcs1p accelerates v-t-SNARE complex formation in vitro, indicating that ArfGAPs may act as folding chaperones. These SNARE complexes were resolved in the presence of ATP by the yeast homologues of alpha-SNAP and NSF, Sec17p and Sec18p, respectively. In addition, Sec18p and Sec17p also recognized the 'activated' SNAREs even when they were not engaged in v/t-SNARE complexes. Here again, the induction of a conformational change by ArfGAPs was essential. Surprisingly, recruitment of Sec18p to SNAREs did not require Sec17p or ATP hydrolysis. Moreover, Sec18p displaced pre-bound Arf1p from SNAREs, indicating that Sec18p may have more than one function: first to ensure that all vesicle coat proteins are removed from the SNAREs before the engagement in a trans-SNARE complex and second to resolve cis-SNARE complexes after fusion has occurred.
|Evidence ID||Analyze ID||Interactor||Interactor Systematic Name||Interactor||Interactor Systematic Name||Type||Assay||Annotation||Action||Modification||Phenotype||Source||Reference||Note|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Gene Ontology Term||Gene Ontology Term ID||Qualifier||Aspect||Method||Evidence||Source||Assigned On||Reference||Annotation Extension|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Phenotype||Experiment Type||Experiment Type Category||Mutant Information||Strain Background||Chemical||Details||Reference|
|Evidence ID||Analyze ID||Regulator||Regulator Systematic Name||Target||Target Systematic Name||Experiment||Conditions||Strain||Source||Reference|